Analysis of spatial and temporal impact differences of birth rate in mainland China

The continuing decline in the birth rate has led to a serious problems, such as the disproportion population structure, severe aging population, which has restricted the country’s economic development. To understand more deeply the geographical differences and influencing factors of the birth rate, this paper collects and organizes the birth population data of 31 provinces in mainland China from 2014 to 2019. The national region is divided into seven natural geographical regions to obtain the spatial hierarchy, and a hierarchical Bayesian spatio-temporal model is established. The model parameters are estimated by the INLA algorithm. The results show that there are significant spatial and temporal differences in birth rates in mainland China, which are reflected mainly in the combination of economic, spatial, temporal, and spatio-temporal interaction effects. With the increase of per capita disposable income, population’s fertility intention decreases, but regional GDP still has a high positive impact on the local birth rate. The spatial and temporal pattern of the birth rate is the remaining explanation. In spatial dimension, the northeast is low, the northwest and southwest are high, and the birth rate has an upward trend from east to west. These trends are caused by unbalanced economic development, different fertility attitudes and differences in fertility security, reflecting regional differences in spatial effects. In the time dimension, from 2014 to 2019, China’s birth rate showed an overall downward trend. However, all regions except the northeast saw a significant but temporary increase in birth rates in 2016 and 2017, reflecting the time effect difference in birth rates.